Vaginal angiofibroma in a dog

Summary Background: Angiofibroma is an uncommon benign mixed mesenchymal tumour occurring mainly in the genital region of human beings. In dogs angiofibroma reported in the frontal sinus, nasal cavity, and skin. Objectives: The authors reported a clinicopathological case of primary vaginal cellular angiofibroma in a 6-year-old female miniature pinscher. Materials and Methods: Surgical biopsy vaginal multilobular, polypoid tumour sample was conserved in 8% formalin for 24 hours at room temperature, embedded in paraffin wax and further processed for sectioning (3–4 µm) and immunohistochemistry (histopathology: hematoxylin and eosin-, Azan-staining; antibodies: anti-vimentin, -smooth muscle actin, -S-100 protein, -c-Kit/CD117, -claudin-5, -pancytokeratin AE1-AE3, and -Ki-67). Results and Discussion: The spindle-shaped tumour cells were arranged haphazardly and showed organization partly in short fascicles. They had bland, oval to fusiform. The cytoplasm was ill-defined, pale eosinophilic. The vascular component, consisted of small- to medium-sized blood vessels. The tumour showed intense vimentin-positivty. The spindle cells were negative for α-SMA, S-100 protein, c-Kit, claudin-5, and pancytokeratin. The vascular components were positive for α-SMA, and claudin-5. Intratumoural mast cells were positive for c-Kit. Ki-67-labeling index was: 12–13%. The definitive diagnosis was primary vaginal cellular angiofibroma. It is the first description of the canine vaginal angiofibroma/benign combinatory mixed tumour in the veterinary literature